According to NASA Blogs:
The CYGNSS launch planned for Wednesday, Dec. 14 is being delayed due to an issue with flight parameter data used by spacecraft software. The issue was discovered during routine testing Tuesday. The new flight parameter data have undergone verification testing on the engineering model, and will be uploaded to the spacecraft on Wednesday. The uploading of new flight data is a very routine procedure, and is expected correct the issue. The next launch attempt will be determined pending the results of ongoing tests.